ENDODONTIC OBTURATOR

Description

TECHNICAL FIELD

[0001] The present invention relates to an appliance for use in filling an endodontically prepared root canal and of the kind comprising

a) a central insertion rod of flexible material, surrounded partly by

b) an elongate filler body of plastic or thermoplastic material.

BACKGROUND ART

[0002] In appliances of this kind, disclosed i.a. by William B. Johnson in United States Patent No. 4,758,156, which forms the basis of the preamble of Claim 1, the central insertion rod is adapted to be severed when the filler body has been placed in its final position in the root canal. This means, of course, that a part of the insertion rod remains permanently in the root canal. In many cases, this does not cause any problems, but - as will be well-known by dentists - teeth having been treated by the use of such an appliance are also frequently in need of a crown.

[0003] As likewise well-known by dentists, tooth crowns have to be anchored to the tooth concerned in a reliable manner, this normally requiring the drilling of at least one suitable anchoring hole. Such drilling is, however, made difficult by the part of the insertion rod remaining in the root canal. Thus, if the insertion rod was made of metal, such as titanium, drilling is almost impossible, while if the insertion rod was made of a hard thermoplastic material, the drilling operation may cause it to melt and clog the drill.

DISCLOSURE OF THE INVENTION

[0004] It is the object of the present invention to provide an appliance of the kind referred to initially, with which it is possible to avoid the problems described above, and this object is achieved with such an appliance, according to the invention being characterized by a core surrounding said rod and surrounded by said filler body and consisting of material that is or may be made sufficiently soft to allow removal of said rod without removal of said filler body. With this arrangement, it is no longer necessary to leave a part of the insertion rod remaining permanently in the root canal and causing the problems described above.

[0005] According to a first embodiment of the invention, the rod may be made of carbon steel. This is a comparatively inexpensive material having excellent qualities with regard to elasticity and strength requisite for the use for which it is intended.

[0006] According to a second embodiment, the core consists of a material capable of being softened by heat. With this embodiment, the insertion rod may be removed easily after having been heated on the part extending outside of the core and the filler body.

[0007] According to a third embodiment, the insertion rod may be helically wound or twisted or formed with a steep thread so as to make it possible to unscrew it from the core, thus facilitating the removal of the insertion rod from the filler body and the core.

[0008] According to a fourth embodiment, the core may consist of or comprise material that is opaque to tissue-penetrating rays. With this embodiment, it is possible to locate the root canal by using x-rays, the core now in this respect playing the same role as previously played by a part of a metal insertion rod remaining in the root canal.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In the following detailed portion of the present description, the invention will be explained in more detail with reference to the exemplary embodiment of an appliance according to the invention diagramatically shown in the single figure.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0010] The endodontic obturator shown in the drawing comprises

• a handle 1, made e.g. from some suitable plastic material,
• an insertion rod 2, made e.g. from carbon steel, and
• a filler body 3 of gutta-percha surrounding the lowermost part of the insertion rod 2.

[0011] The three parts 1-3 described in the previous paragraph may be said to belong to the prior art. The novel feature of the invention is represented by a core 4 surrounding the insertion rod 2 and itself being surrounded by the filler body 3. The core 4 is made of a material that is sufficiently soft, or can be made sufficiently soft, so as to make it possible to remove the insertion rod 2 from the filler body 3, when the latter has been placed in its final position in a root canal of a tooth (not shown). Persons with knowledge of plastic materials will know how to choose the correct material for the core 4 according to requirements. In practice, the appliance is used in the following manner.

[0012] When the root canal has been prepared, the appliance is inserted in the canal with the filler body 3 leading, possibly after suitable pre-heating of the filler body to make it sufficiently soft to adapt itself to the walls of the root canal. During the insertion, the device is held and moved by means of the handle 1.

[0013] When the filler body 3 has been placed in its final position in the root canal, and sufficient time has elapsed to allow it to cure or set (if necessary), the insertion rod 2 is removed by means of the handle 1. If the surface of the insertion rod 2 is smooth, it may be removed by simply pulling the handle 1, but if it is helically wound or twisted or formed with a steep thread, it may be unscrewed by turning the handle 1 in the appropriate direction.

[0014] If the core 4 is made of a thermoplastic material that is relatively stiff at the temperatures encountered, the removal of the handle 1 may be facilitated by gently heating the part of the insertion rod 2 not being covered with core material.

[0015] When the insertion rod 2 has been removed, any excess core material may be removed, after which the root canal is closed and provided with a top filling in the normal manner. At this stage only the filler body 3 and the core 4 remain in the part of the root canal, into which they were inserted. It is now possible to drill an anchoring hole into or intersecting the root canal without the risk of the drill encountering materials causing problems of the kind referred to initially.

[0016] Obviously, both the filler body 3 and the core 4 will have to be made of suitable tissue-friendly materials.

[0017] The dimensions of the insertion rod 2, the filler body 3 and the core 4 may be varied according to need.

Claims

1. Appliance for use in filling an endodontically prepared root canal and of the kind comprising

a) a central insertion rod (2) of flexible material, surrounded partly by

b) an elongate filler body (3) of plastic or thermoplastic material,
characterized by

c) a core (4) surrounding said rod (2) and surrounded by said filler body (3) and consisting of material that is or may be made sufficiently soft to allow removal of said rod (2) without removal of said filler body (3).

2. Appliance according to claim 1, characterized in that said rod (2) is made of carbon steel.

3. Appliance according to claim 1 or 2, characterized in that said core (4) consists of a material capable of being softened by heat.

4. Appliance according to any one or any of the claims 1-3, characterized in that said rod (2) is helically wound or twisted or formed with a steep thread so as to enable it to be unscrewed from said core (4).

5. Appliance according to any one or any of the claims 1-4, characterized in that said core (4) consists of or comprises material that is opaque to tissue-penetrating rays.

Ansprüche

1. Vorrichtung zur Verwendung beim Füllen eines endodontisch vorbereiteten Wurzelkanals und derjenigen Art, die folgendes aufweist:

a) einen mittleren Einführstab (2) aus flexiblem Material, der teilweise durch

b) einen länglichen Füllkörper (3) aus plastischem oder thermoplastischem Material umgeben ist,
gekennzeichnet durch

c) einen Kern (4), der den Stab (2) umgibt und durch den Füllkörper (3) umgeben ist und aus einem Material besteht, das hinreichend weich ist oder gemacht werden kann, um eine Entfernung des Stabes (2) ohne eine Entfernung des Fullkörpers (3) zu gestatten.

2. Vorrichtung nach Anspruch 1,
dadurch gekennzeichnet, daß
der Stab (2) aus Kohlenstoffstahl ausgeführt ist.

3. Vorrichtung nach Anspruch 1 oder 2,
dadurch gekennzeichnet, daß
der Kern (4) aus einem Material besteht, das durch Wärme erweicht werden kann.

4. Vorrichtung nach zumindest einem der Ansprüche 1 bis 3,
dadurch gekennzeichnet, daß
der Stab (2) derart schraubenförmig gewunden oder gedreht oder mit einem steilen Gewinde ausgebildet ist, daß er von dem Kern (4) abgeschraubt werden kann.

5. Vorrichtung nach zumindest einem der Ansprüche 1 bis 4,
dadurch gekennzeichnet, daß
der Kern (4) aus einem Material besteht oder ein Material aufweist, das undurchlässig für Gewebe durchdringende Strahlen ist.

Revendications

1. Appareil destiné à être utilisé pour le remplissage d'un canal radiculaire préparé de manière endodontique et du type comprenant :

a) une tige centrale d'insertion (2) en matériau flexible, entourée partiellement par

b) un corps de remplissage allongé (3) en matériau plastique ou thermoplastique,
caractérisé par :

c) une partie centrale ou coeur (4) entourant ladite tige (2) et entourée par ledit corps de remplissage (3) et consistant en un matériau qui est ou peut être rendu suffisamment mou pour permettre l'enlèvement de ladite tige (2) sans enlever ledit corps de remplissage (3).

2. Appareil selon la revendication 1, caractérisé en ce que ladite tige (2) est réalisée en acier au carbone.

3. Appareil selon la revendication 1 ou 2, caractérisé en ce que ladite partie centrale (4) consiste en un matériau capable d'être ramolli par la chaleur.

4. Appareil selon l'une ou l'une quelconque des revendications 1 à 3, caractérisé en ce que ladite tige (2) est enroulée en hélice, ou tordue, ou formée avec un filetage à grand pas, de façon à permettre de la dévisser de ladite partie centrale (4).

5. Appareil selon l'une ou l'une quelconque des revendications 1 à 4, caractérisé en ce que ladite partie centrale (4) consiste en ou comprend un matériau qui est opaque au rayonnement pénétrant les tissus.

Drawing